HT4100 4.1, 4.5, 4.9 Discussion, Dead DeVille Aftermath! in Cadillac Engine Technical Discussion; Got it back from the dealer today and it was all fixed.
The problem was the downstream O2 sensor had ...

Dead DeVille Aftermath!

Got it back from the dealer today and it was all fixed.

The problem was the downstream O2 sensor had fouled the spark plug on cylinder 2 (at the back, farthest to the left). Now of course, the home mechanic can't get at the downstream sensor and so they had to replace it.

Essentially it rendered cylinder 2 inoperative and caused it to run rich, hence the misfire.

Re: Dead DeVille Aftermath!

"The problem was the downstream O2 sensor had fouled the spark plug on cylinder 2 (at the back, farthest to the left). Now of course, the home mechanic can't get at the downstream sensor and so they had to replace it."

i think they lied to you , i replaced boath of my sensors , at home in the driveway with a florrjack , jackstand and the wrench (13/16 i belive), then turned around and changed all the plugs ...i never do the plugs again tho , god that was a awful job

Re: Dead DeVille Aftermath!

Originally Posted by Stoneage_Caddy

"The problem was the downstream O2 sensor had fouled the spark plug on cylinder 2 (at the back, farthest to the left). Now of course, the home mechanic can't get at the downstream sensor and so they had to replace it."

i think they lied to you , i replaced boath of my sensors , at home in the driveway with a florrjack , jackstand and the wrench (13/16 i belive), then turned around and changed all the plugs ...i never do the plugs again tho , god that was a awful job

I'm surprised you found them that difficult! Sure it was hard, but in the end, and after coming close to rupturing some A/C lines, I was VERY proud with my job! New wires, cap, rotor, and NGK G-Power plugs made that thing fly! Nothing pleases me more with that car then knowing that my plug job went flawlessly (under normal circumstances).

Re: Dead DeVille Aftermath!

alot of the difficulty was on my part to be honest , it was tight on that rear bank but i have a ruptured disc in my back so screwing around on that rear bank,leaned over the front of the car did a number on me , it still makes my top 10 of worst plug change access , could be worse tho, could be a late 60s 427 stang , according to ford the engine HAS to be pulled to change the plugs and back then there was no platnum plugs or and kind of 100,000 mile tuneup intervals

Re: Dead DeVille Aftermath!

Originally Posted by Stoneage_Caddy

alot of the difficulty was on my part to be honest , it was tight on that rear bank but i have a ruptured disc in my back so screwing around on that rear bank,leaned over the front of the car did a number on me , it still makes my top 10 of worst plug change access , could be worse tho, could be a late 60s 427 stang , according to ford the engine HAS to be pulled to change the plugs and back then there was no platnum plugs or and kind of 100,000 mile tuneup intervals

lol poor stoneage!

Hmmmm....title....do you get seasick in your caddy? I do. LOL bounce! I frequently bounce the car when I come to a stop. Its funny! We got chicks that way! Me and a buddy of mine were driving along, coming up to a light. We were playing 'Cadillac Pimpin' by Youngbloodz and so I decide to hit the brake intermittently to make the car appear as if it has hydraulics. So these chicks next to us are laughing at out patheticism and we basically changed course and followed them to their house. lol it was fun.

For the rest of yous me and stoneage are officially brothers. Both 1994's, both 4.9's!

Re: Dead DeVille Aftermath!

sure do get sea sick , there a section of i275 that has some very nasty fast elevation changes and the damn thing begins to feel like something from the movie "perfect storm "

its also why i call it the "nimitz" editon (named for the navy class ship) , tho her offical name is gladdis as in the singing overweight diva from the late 60s , approprate for a car with many diva like qualitys ,mostly the ammount of attention it reqiures to do its job

yah i guess we are just about the only 2 94 devilles with 4.9 power and i bet boath of us are over 100,000 miles , of coarse you may be measureing in kms

matter of fact she turned over to 114000 today , and did it ping free!!!!

Re: Dead DeVille Aftermath!

sure do get sea sick , there a section of i275 that has some very nasty fast elevation changes and the damn thing begins to feel like something from the movie "perfect storm "

its also why i call it the "nimitz" editon (named for the navy class ship) , tho her offical name is gladdis as in the singing overweight diva from the late 60s , approprate for a car with many diva like qualitys ,mostly the ammount of attention it reqiures to do its job

yah i guess we are just about the only 2 94 devilles with 4.9 power and i bet boath of us are over 100,000 miles , of coarse you may be measureing in kms

matter of fact she turned over to 114000 today , and did it ping free!!!!

Re: Dead DeVille Aftermath!

In the winter, they actaully help (they let the tranny heat up faster)...... But in the hot summer, they do more harm than good......

If you want to heat up the tranny really good before you go out, put it in gear and apply the brake for about 25 seconds..... That is when the most heat is created, in gear and stopped....... I always put my car in neutral when im at a stoplight for a while.....